Tumbler lock with automatic key ejector



March 25, 1969 E. N. JAQBl 3,434,311

TUMBLER LOOK WITH AUTOMATIC KEY EJECTOR Filed July 24, 1967 Sheet of 4 A. I r

I March 25, 1969 JACOB] 3,434,317

TUMBLER LOCK WITH AUTOMATIC KEY EJECTOR Filed July 24, 1967 Sheet 2 of 4 as M 1/ mum f Q\ ///V////l/ ///1// .44- I 45 Z5: F: I I] I IdWaz'dAZfimbz I March 25, 1969 E. N. JACOBI 1 3,434,317

TUMBLER LOCK WITH AUTOMATIC KEY EJECTOR Filed July 24, 1967 Sheet 3 of 4 March 25, 1969 JACOB] 3,434,317

TUMBLER LOCK WITH AUTOMATIC KEY EJECTOR Filed July 24, 1967 Sheet 4 of 4 l'awardfll Jamal United States Patent US. Cl. 70388 11 Claims ABSTRACT OF THE DISCLOSURE A key controlled tumbler lock in which automatic ejection of the key is effected by a finger on a rack which slides in a guideway in one side wall of the lock casing with the finger projecting laterally into the keyway when the cylinder is in its locked position of rotation to have the end of the key collide therewith during insertion of the key, the rack being biased towards the front of the lock by a torsion spring having one end anchored to the casing and its other end attached to a pinion journaled in the casing and meshing with the rack. The insertion of the key thus rotates the pinion and loads the spring. In one embodiment of the disclosure, the rack consists of two side-by-side sections having a lost motion connection therebetween and successively meshing with the pinion so as to minimize the distance the rack protrudes from the rear of the lock casing upon insertion of the key.

This invention relates to key controlled tumbler locks especially adapted for use with automobile ignition switches. j

The broad purpose and object of the invention is to provide for automatic ejection of the key from the lock whenever the key is turned to the OFF position of the switch controlled thereby. This is accomplished by means of a spring which is tensioned orloaded during insertion of the key, restrained when the key is turned from its insertion and withdrawal position, and again released to,

eject the key when it is returned to that position.

Although various key ejecting devices have been developed and proposed heretofore, as evidenced, for instance, by the Jacobi Patent No. 1,738,105, and the recently issued Turman Patent No. 3,320,782, they have all been subject to the objection of requiring substantial space at the rear end of the lock to accommodate the spring which provides the ejecting force and the mechanism by which the insertion of the key loads the spring and the released force of the spring acts to eject the key.

In addition, some of the earlier key ejecting devices could not be adapted to pin tumbler locks.

This invention overcomes these and other objections to prior locks equipped with key ejection means by making the ejection mechanism more compact and locating it in a side wall of the lock'casing alongside the cylinder, rather than rearwardly of the lock cylinder where it would seriously increase space requirements and interfere with the ignition switch or other mechanism actuated by rotation of the lock cylinder.

More specifically, the invention achieves its purpose through theuse of a torsion spring mounted in the lock casing medially of its front and rear ends, and a rack and pinion mechanism through which the spring is tensioned or loaded by insertion of the key-and through which the spring force acts, when released, to eject the key.

- With these observations and objects in mind, the manner in which the invention achieves its purpose will be appreciated from the following description and accompanying drawings. This disclosure is intended merely to exemplify and explain the invention. The invention is 3,434,317 Patented Mar. 25, 1969 pin tumbler lock having one form of the key ejection device of this invention incorporated therein;

FIGURE 2 is a view similar to FIGURE 1, but with the key inserted into the lock;

FIGURE 3 is a cross sectional view through FIGURE 2 on the plane of the line 3-3;

FIGURE 4 is a fragmentary side view illustrating a detail of the structure shown in FIGURE 3;

FIGURE 5, like FIGURE 1, is a longitudinal sectional view through a pin tumbler lock but equipped with key ejecting mechanism even more compact than that shown in FIGURES 1-4;

FIGURE 6 is a longitudinal sectional view through FIGURE 5 on the plane of the line 66, said view showing the mechanism in its normal at rest condition, i.e., without a key in the lock;

FIGURE 7 is a cross sectional view through FIG- URE 5 on the plane of the line 7-7;

.FIGURES 8 and 9 are longitudinal sectional views similar to FIGURE 6, but showing the mechanismin the conditions which obtain when the key is partially and fully inserted;

FIGURE 10 is a longitudinal sectional view similar to FIGURE 5, but with a key in the lock; and

FIGURES 11, 12 and 13 are perspective views of the rack and pinion mechanism employed in the more compact version of the invention shown in FIGURES 5-10, respectively showing the relationship of the parts when no key is present, when it i partially inserted and when it is fully inserted.

Referring now more particularly to the accompanying drawings, in which like numerals designate: like parts throughout the several views, and considering first the embodiment of the invention shown in FIGURES 1-4, the numeral 5 designates the casing of a conventional pin tumbler lock, having a bore 6 in which a cylinder 7 is rotatably received. The cylinder is secured against rotation by a plurality of spring pressed pin tumblers 8 except upon insertion into its keyway 9 of a proper key 10. When thus released, the cylinder may be turned by means of the key to actuate whatever mechanism or device the lock controls-as, for instance, an automobile ignition switch, and to which the lock cylinder is coupled by a driver 11 projecting from the rear or inner end of the cylinder. Since it forms no part of this invention, the mechanism controlled by the lock has not been shown.

The keyway 9 opens to the side of the cylinder and extends longitudinally from the outer face of a collar 12 on the front end of the cylinder to the rear end portion of the cylinder where it communicates with a circumferential groove 13 in the cylinder. This groove has a forwardly facing side wall 14, a portion of which is opposite and in line with the rear end of the keyway, and a rearwardly facing side wall 15 at which the keyway terminates.

One of the purposes of the groove 13 is to receive a tongue 16 which is an integral part of the casing, and whichwhen engaged in the groove--cooperates with the collar 12 atthe front end of the cylinder to secure the cylinder against endwise movement in the casing bore. Entry of the tongue into the groove during assembly of the cylinder with the casing, as well as exit thereof from the groove to permit removal of the cylinder, is possible only when the cylinder is in a predetermined position of rotation. This feature of the lock, however, forms no part of the present invention and in fact is conventional.

The other purpose of the groove 13 has to do with key ejection which is the real concern of this invention.

In both embodiments of the invention illustrated, key ejection is produced by a torsion spring 20* acting through a pinion 21 meshing with a rack 22. The rack 22 is constrained to endwise movement along a path parallel to the cylinder axis and has a finger or abutment 23 which projects laterally into the open edge of the keyway to engage the nose of the key.

The rack is guided and constrained to its desired endwise movement by being slidably received in a longitudinal groove 24 in the wall of the casing bore 6. This groove extends for the full length of the casing and hence is closed at its front by the collar 12 of the cylinder which covers the front end of the cylinder, but open at its rear end where it, like the keyway, communicates with the circumferential groove 13. From FIGURE 3 it will be seen that the cylinder wall confines the rack to the groove 24, and that this groove is so located that the open edge of the keyway is in line with and opens to the groove in the locked position of the cylinder.

This is the only position of the cylinder at which key insertion and removal is possible; and, where the lock controls an ignition switch, this locked position of the cylinder corresponds to the OFF position of the switch.

The contiguity of the groove 24 and the open edge of the keyway when the cylinder is in its locked position of rotation enables the finger or abutment 23 to project into the keyway and travel along the length thereof.

The pinion 21 is assembled with the casing by being received in a cylindrical cavity 25 in a boss 26 at the underside of the casing. A shaft 27 fixed to the pnion, or preferably integral therewith, is journalled in a bore 28 through the bottom wall of the cavity to rotatably mount the pinion, and the torsion spring 20 is coiled about the end portion of this shaft which protrudes from the side of the boss 26. One end of the spirng is anchored to the casing, as at 29, and its other end is attached to the shaft 27 by being received in a notched slot 30 formed in the end of the shaft.

The spring is preloaded and hence at all times applies torque to the pinion in the direction to propel the rack 22 towards a defined forward position established by engagement of the front end of the rack with the inner face of the collar 12. In this position of the rack, the finger or abutment 23which is preferably integral with the rack-- is substantially in line with the foremost tumbler so that upon insertion of the key its nose collides with the finger before the key is inserted far enough to keep it from falling if released. Thus during ejection of the key by return of the finger or abutment to its defined forward position, the key will definitely drop from the lock, unless it is being held.

As the key is inserted, the finger or abutment 23 and, of course, also the rack, is carried along with the key with the result that the spring is further tensioned or loaded. When the finger or abutment is pushed out of the rear end of the keyway and into the groove 13 against its forwardly facing side 14, the key is properly located to free the cylinder for rotation. The reception of the finger in the groove 13, of course, permits rotation of the cylinder without hindrance from the ejection mechanism.

As soon as the cylinder is rotated from its locked position the rearwardly facing side 15 of the groove 13 rides in front of the finger or abutment 23 and thereby restrains the spring and in effect cocks the mechanism to be triggered for key ejecting action by return of the cylinder to its locked, switch OFF position.

While the placement of the ejection mechanism in the side of the lock casing alongside the cylinder-rather than beyond its rear end-achieves unprecedented compactness, for some installations the rack still protrudes too far beyond the rear end of the casing. This objection is avoided, or at least greatly minimized, in the embodiment of the invention illustrated in FIGURES 513.

In this case, the rack, designated generally by the numeral 22', is divided into two overlying sections 35 and 36 which successively mesh with the pinion 21'. To make this possible, the pinion is long enough to encompass both racks.

The rack section 35 has the finger or abutment 23 formed thereon so that it must travel the full distance involved in key insertion. Under the circumstances, if objectionable protrusion of the rack beyond the rear end of the lock casing is to be avoided, the rack section 35 must be shorter than that full distance. This means that although the rack section 35 has teeth from end to end, it can not maintain meshing engagement with the pinion throughout key insertion. But a force transmitting motion imparting connection must be maintained between the finger or abutment and the spring which, as before, reacts between the casing and the pinion. Hence, when the rack section 35 leaves the pinion, the other rack section 36 must take over.

Accordingly the two racks have a lost motion driving connection 37 therebetween which is taken up during the interval the rack section 35 is in mesh with the pinion and imparts spring loading rotation thereto as the key is inserted. During this interval, an untoothed portion 38 on the rack section 36 and an untoothed portion 39 on the pinion are opposite one another, as depicted in FIGURE 11.

Meshing engagement between the pinion and the rack section 36 does not occur until the lost motion between the sections is taken up and the two sections begin to move in unison. This takes place just before the rack section 35 leaves the pinion so that during a short medial portion of the insertion of the key, both rack sections are in mesh with the pinion. FIGURE 12 shows the relationship of the parts the instant the lost motion between the rack sections is taken up and meshing engagement between the section 36 and the pinion is about to take place.

After the rack section 35 leaves the pinion, section 36 being in mesh therewith, maintains the force transmitting motion imparting connection between the pinion and the finger or abutment, as illustrated in FIGURE 13.

Obviously, during ejection of the key which, as before, occurs automatically upon return of the lock cylinder to its locked, switch OFF position of rotation, the transfer of force from the pinion to the finger or abutment 23 involves successive meshing engagement of the pinion first with the rack section 36 and then with the section 35.

As can be best appreciated from FIGURE 10, in the fully cocked condition of the mechanism when the key is in cylinder releasing position, the rack protrudes but a very short distance beyond the rear end of the casing.

A factor not heretofore mentioned, but which plays a part in minimizing the maximum distance the rack protrudes from the rear of the lock is the location of the pinion substantially equidistant from the ends of the casing, as distinguished from its location near the rear end of the casing, which is necessary with the single rack construction of FIGURES 1-4.

While both rack sections 35 and 36 could be planar members, either stampings or die castings, it has been found desirable to make the section 35 channel-shaped in cross section with upper and lower flanges 35a and 35b connected by a web 350. The upper flange has the finger or abutment 23 formed thereon and the lower flange has the rack teeth. The other rack section 36 which is simply a fiat member, is slidably received between the flanges. The outer edge of this other section has teeth along its front half and for the remainder of its length this edge is smooth to provide the untoothed portion 38.

The rear edge of the rack section 36 and the web 350 of the channel shaped rack section provide contiguous surfaces, one of which has a lug 40 thereon and the other has an elongated notch 41 therein to receive the lug. This forms the lost motion driving connection between the two rack sections, and as shown the lug is preferably on the web.

In the previously described embodiment of the invention, the pinion is mounted with its axis transverse to the plane of the keyway when the cylinder is in its locked position of rotation, but in this multiple rack form of the invention the pinion 21' has its shaft 44 journalled in a bore 45 in a boss 46 at the side of the casing to turn on an axis parallel to the plane of the keyway when the cylinder is in its locked position of rotation. The upper end portion of the shaft has the torsion spring coiled thereabout with one end of the spring anchored to the casing and its other end attached to the shaft, and the pinion is at the underside of the boss opposite the open side of a longitudinal groove 42 in the bottom portion of the casing. The assembled rack sections are slidably received in the groove -42 and are retained therein by the pinion.

A slot 43 connecting the groove 42 with the bore of the casing accommodates the finger or abutment 23 and enables it to project laterally into the open edge of the keyway and travel along the length thereof between its defined forward position and its rearmost position in line with the circumferential groove 13.

From the foregoing description taken with the accompanying drawings, it will be apparent to those skilled in this art that this invention constitutes a substantial improvement in key controlled tumbler locks equipped with automatic key ejection.

What is claimed as my invention is:

1. A key controlled tumbler lock having a casing with a bore, a cylinder rotatable in the bore and having a keyway and tumblers to secure the cylinder against rotation from a locked position except when a proper key has been inserted into the keyway, the key being insertable and removable only when the cylinder is in its locked position of rotation, said lock being characterized by means for automatically ejecting the key when the cylinder is rotated thereby from an unlocked position to its locked position of rotation, comprising:

(A) rack means;

(B) a fiat sided slot in the casing extending lengthwise of and in open communication with its bore, said slot having the rack means slidably received therein and constraining the same to endwise translatory movement along a path parallel to the cylinder axis to and from a defined forward position;

(C) a pinion meshing with the rack means mounted for rotation about an axis fixed with respect to the casing and transverse to the cylinder axis and operable upon rotation to impart endwise movement to the rack means;

(D) spring means reacting between the pinion and casing biasing the pinion to rotate in the direction to yieldingly maintain the rack means at its defined forward position;

(B) an abutment on the rack means projecting into the keyway when the rack means is in its defined forward position, to have the end of the key collide with its forwardly facing surface as the key is inserted, so that insertion of the key results in rearward displacement of the rack means and rotation of the pinion in the direction to increase the spring bias thereon, whereby said spring means is effective, when unrestrained, to propel the rack means towards its defined forward position and thereby eject the key; and

(F) means rendered effective by rotation of the cylinder away from its locked position of rotation, for

transferring the thrust of the spring means from the key to the cylinder.

2. The lock of claim 1, wherein said last named means comprises.

a rearwardly facing shoulder on the cylinder to which the rear end of the keyway opens, and against which the forward facing surface of the abutment bears when the cylinder is turned from its locked position.

3. The lock of claim 2, further characterized by a forwardly facing shoulder on the rear end of the cylinder spaced from said rearwardly facing shoulder, said shoulders defining the sides of a circumferential groove to receive the abutment when the cylinder is turned from its locked position of rotation.

4. The lock of claim 3, wherein said forwardly facing shoulder has a portion thereof in line with the path of the abutment to limit its rearward displacement during insertion of the key and thereby define the operative cylinder releasing position of the key.

5. A key controlled tumbler lock having a casing with front and rear ends and a bore extending therethrough, a cylinder rotatable in the bore and having a keyway and an actuator projecting beyond the rear end of the casing, and tumblers to secure the cylinder against rotation from a locked position except when a proper key has been inserted into the keyway, the key being insertable and removable only when the cylinder is in its locked position of rotation, said lock being characterized by means for automatically ejecting the key when the cylinder is rotated thereby from an unlocked position to its locked position of rotation, comprising:

(A) a finger slideably mounted in the casing for movement lengthwise thereof, said finger projecting laterally into the bore of the casing to be received in and travel along the keyway when the cylinder is in its locked position of rotation;

(B) preloaded spring means mounted on the casing between its front and rear ends for yieldingly maintaining the finger at a defined forward position in which it is engaged by the end of the key during insertion thereof before the key is in far enough to remain in place if released, so that during insertion of the key the finger is moved towards the rear end of the keyway a distance substantially equal to the entire length of the keyway; and

(C) means providing a force transmitting motion imparting connection between the finger and the spring means by which the force of the spring means is applied to the finger and rearward movement of the finger further loads the spring means, said connection means comprising (1) a plurality of motion imparting members slideably mounted on the casing for movement lengthwise thereof;

(2) means providing a positive motion imparting connection between one of said members and the finger so that said one member moves the full distance the finger travels, said one member being shorter in the direction of its sliding motion than the distance the finger travels;

(3) means operative only during an initial portion of the rearward travel of the finger to provide a motion imparting connection between said one member and the spring means;

(4) means providing a lost motion driving connection between said members whereby the finger produced motion of said one member may be imparted to another of said members; and

(5) means operative after the lost motion of said driving connection between said members is taken up and said one member no longer has a motion imparting connection with the spring means to provide a motion imparting connection between said other member and the spring means, whereby the force transmitting connection between the finger and the spring means is maintained throughout the full rearward travel of the finger despite the fact that said one member is shorter than the distance the finger travels.

6. The lock of claim 5, wherein said slideably mounted motion imparting members are racks, and the connections thereof with the spring means comprise a pinion rotatably mounted on the casing between the front and rear ends thereof for rotation about an axis transverse to the cylinder axis, the teeth of the pinion and the racks being so arranged that the racks successively have driving relationship with the pinion, and wherein the spring means is a torsion spring with one end anchored to the casing and its other end connected to the pinion.

7. The lock of claim 6, wherein the mounting for the pinion comprises a boss on the casing having a bore therethrough, the axis of which is parallel with the plane of the keyway when the cylinder is in its locked position of rotation, and a shaft projecting from the pinion and journalled in said bore.

8. The lock of claim 7, wherein the pinion is on one end of said shaft and the torsion spring encircles the other end portion of the shaft.

9. The lock of claim 6, wherein the racks are slideably received in a groove in the casing extending lengthwise of its bore, one side of the groove having a slot parallel to the axis of the bore and communicating the groove with the bore, the finger projecting through said slot.

10. The lock of claim 9, wherein said rack which has a positive motion imparting connection with the finger has a channel shaped cross section which substantially fills the cross section of the groove with one flange thereof in sliding engagement with the slotted side of the groove, the finger being fixed to said flange, and the teeth of said rack being on the edge of its other flange.

11. The lock of claim 10, wherein said rack of channel shaped cross section embraces another of said racks with the untoothed back edge thereof riding on the web of the channel to provide a pair of contiguous surfaces, and wherein the lost motion driving connection between said racks comprises a lug projecting from one of said surfaces riding on a notch in the other surface.

References Cited UNITED STATES PATENTS 1,738,105 12/1929 Jacobi 388 1,798,917 3/1931 Van Degrift 70--388 X 3,005,331 10/1961 Roberson 70-388 3,019,634 2/ 1962 Roberson 70-388 3,320,782 5/1967 Turman 70-388 MARVIN A. CHAMPION, Primary Examiner.

PERRY TEITELBAUM, Assistant Examiner.

U.S. Cl. X.R. 70-4 21 

